#! /usr/bin/perl -w
# Some scripts for handling mailto URLs within lynx via an interactive form
#
# Warning: this is a quick demo, to show what kinds of things are possible
# by hooking some external commands into lynx. Use at your own risk.
#
# Requirements:
#
# - Perl and CGI.pm.
# - A "sendmail" command for actually sending mail (if you need some
# other interface, change the code below in sub sendit appropriately).
# - Lynx compiled with support for lynxcgi, that means EXEC_CGI must have
# been defined at compilation, usually done with
# ./configure --enable-cgi-links
# - Lynx must have support for CERN-style rules as of 2.8.3, which must
# not have been disabled at compilation (it is enabled by default).
#
# Instructions:
# (This is for people without lynxcgi experience; if you are already
# use lynxcgi, you don't have to follow everything literally, use
# common sense for picking appropriate file locations in your situation.)
#
# - Make a subdirectory 'lynxcgi' under you home directory, i.e.
# mkdir ~/lynxcgi
# - Put this three script file mailto-form.pl there and make it
# executable. For example,
# cp mailto-form.pl ~/lynxcgi
# chmod a+x ~/lynxcgi/mailto-form.pl
# - Edit mailto-form.pl (THIS FILE), there are some strings that
# that need to be changed, see ### Configurable variables ###
# below.
# - Allow lynx to execute lynxcgi files in that directory, for example,
# put in your lynx.cfg file:
# TRUSTED_LYNXCGI:<tab>/home/myhomedir/lynxcgi/mailto-form.pl
# where <tab> is a real TAB character and you have to put the real
# location of your directory in place of "myhomedir", of course.
# The '~' abbreviation cannot be used.
# You could also just enable execution of all lynxcgi scripts, by
# not having any TRUSTED_LYNXCGI options in lynx.cfg at all, but
# that can't be recommended.
# - Tell lynx to actually use the lynxcgi scripts for mailto URLs.
# There are two variants:
# a) Redirect "mailto"
# Requires patched lynx, currently not yet in the developent code.
# Use the following two lines in the file that is configured as
# RULESFILE in lynxcfg:
# PermitRedirection mailto:*
# Redirect mailto:* lynxcgi:/home/myhomedir/lynxcgi/mailto-form.pl?from=myname@myhost&to=*
# You can also put them directly in lynx.cfg, prefixing each with
# "RULE:". Replace ""myhomedir", "myname", and "myhost" with your
# correct values, of course.
# b) Redirect "xmailto"
# Requires defining a fake proxy before starting lynx, like
# export xmailto_proxy=dummy # or for csh: setenv xmailto_proxy dummy
# Requires that you change "mailto" to "xmailto" each time you want
# to activate a mailto link. This can be done conveniently with
# a few keys: 'E', ^A, 'x', Enter.
# Use the following two lines in the file that is configured as
# RULESFILE in lynxcfg:
# PermitRedirection xmailto:*
# Redirect xmailto:* lynxcgi:/home/myhomedir/lynxcgi/mailto-form.pl?from=myname@myhost&to=*
# You can also put them directly in lynx.cfg, prefixing each with
# "RULE:". Replace ""myhomedir", "myname", and "myhost" with your
# correct values, of course.
#
# Limitations:
#
# - Only applies to mailto URLs that appear as links or are entered at
# a 'g'oto prompt. Does not apply to other ways of sending mail, like
# the 'c' (COMMENT) key, mailto as a FORM action, or mailing a file
# from the 'P'rinting Options screen.
# - Nothing is done for charset labelling, content-transfer-encoding
# of non-ASCII characters, and other MIME niceties.
#
# Klaus Weide 20000712
########################################################################
########## Configurable variables ######################################
$SENDMAIL = '/usr/sbin/sendmail';
# The location of your sendmail binary
$SELFURL = 'lynxcgi:/home/lynxdev/lynxcgi/mailto-form.pl';
# Where this script lives in URL space
$SEND_TOKEN = '/vJhOp6eQ';
# When found in the PATH_INFO part of the URL,
# this causes the script to actually send mail
# by calling $SENDMAIL instead of just throwing
# up a form. CHANGE IT! And don't tell anyone!
# Treat it like a password.
# Must start with '/', probably should have only
# alphanumeric ASCII characters.
## Also, make sure the first line of this script points
## to your PERL binary
########## Nothing else to change - I hope #############################
########################################################################
use CGI;
$|=1;
### Upcase first character
##sub ucfirst {
## s/^./\U$1/;
##}
# If there are multiple occurrences of the same thing, how to join them
# into one string
%joiner = (from => ', ',
to => ', ',
cc => ', ',
subject => '; ',
body => "\n\n"
);
sub joiner {
my ($key) = @_;
if ($joiner{$key}) {
$joiner{$key};
} else {
" ";
}
}
# Here we check whether this script is called for actual sending, rather
# than form generation. If so, all the rest is handled by sub sendit, below.
$pathinfo = $ENV{'PATH_INFO'};
if (defined($pathinfo) && $pathinfo eq $SEND_TOKEN) {
$q = new CGI;
print $q->header('text/plain');
sendit();
exit;
}
$method = $ENV{'REQUEST_METHOD'};
$querystring = $ENV{'QUERY_STRING'};
if ($querystring) {
if ($method && $method eq "POST" && $ENV{'CONTENT_LENGTH'}) {
$querystring =~ s/((^|\&)to=[^?&]*)\?/$1&/;
$q0 = new CGI;
$q = new CGI($querystring);
@fields = $q0->param();
foreach $key (@fields) {
@vals = $q0->param($key);
# print "Content-type: text/html\n\n";
# print "Appending $key to \$q...\n";
$q->append($key, @vals);
# print "<H2>Current Values in \$q0</H2>\n";
# print $q0->dump;
# print "<H2>Current Values in \$q</H2>\n";
# print $q->dump;
}
} else {
$querystring =~ s/((^|\&)to=[^?&]*)\?/$1&/;
$q = new CGI($querystring);
}
} else {
$q = new CGI;
}
print $q->header;
$long_title = $ENV{'QUERY_STRING'};
$long_title =~ s/^from=([^&]*)\&to=//;
$long_title = "someone" unless $long_title;
$long_title = "Compose mail for $long_title";
if (length($long_title) > 72) {
$title = substr($long_title,0,72) . "...";
} else {
$title = $long_title;
}
$long_title =~ s/&/&/g;
$long_title =~ s/</</g;
print
$q->start_html($title), "\n",
$q->h1($long_title), "\n",
$q->start_form(-method=>'POST', -action => $SELFURL . $SEND_TOKEN), "\n";
print "<TABLE>\n";
@fields = $q->param();
foreach $key (@fields) {
@vals = $q->param($key);
if (scalar(@vals) != 1) {
print "multiple values " . scalar(@vals) ." for $key!\n";
$q->param($key, join (joiner($key), @vals));
}
}
foreach $key (@fields) {
$_ = lc($key);
if ($_ ne $key) {
print "noncanonical case for $key!\n";
$val=$q->param($key);
$q->delete($key);
if (!$q->param($_)) {
$q->param($_, $val);
} else {
$q->param($_, $q->param($_) . joiner($_) . "$val");
}
}
}
foreach $key ('from', 'to', 'cc', 'subject') {
print $q->Tr,
$q->td(ucfirst($key) . ":"),
$q->td($q->textfield(-name=>$key,
-size=>60,
-default=>$q->param($key))), "\n";
$q->delete($key);
}
# Also pass on any unrecognized header fields that were specified.
# This may not be a good idea for general use!
# At least some dangerous header fields may have to be suppressed.
@keys = $q->param();
if (scalar(@keys) > (($q->param('body')) ? 1 : 0)) {
print "<TR><TD colspan=2><EM>Additional headers:</EM>\n";
foreach $key ($q->param()) {
if ($key ne 'body') {
print $q->Tr,
$q->td(ucfirst($key) . ":"),
$q->td($q->textfield(-name=>$key,
-size=>60,
-default=>$q->param($key))), "\n";
}
}
}
print "</TABLE>\n";
print $q->textarea(-name=>'body',
-default=>$q->param('body')), "\n";
print "<PRE>\n\n</PRE>", "\n",
$q->submit(-value=>"Send the message"), "\n",
$q->endform, "\n";
print "\n";
exit;
# This is for header field values.
sub sanitize_field_value {
my($val) = @_;
$val =~ s/\0/./g;
$val =~ s/\r\n/\n/g;
$val =~ s/\r/\n/g;
$val =~ s/\n*$//g;
$val =~ s/\n+/\n/g;
$val =~ s/\n(\S)/\n\t$1/g;
$val;
}
sub sendit {
open (MAIL, "| $SENDMAIL -t -oi -v") || die ("$0: Can't run sendmail: $!\n");
@fields = $q->param();
foreach $key (@fields) {
@vals = $q->param($key);
if (scalar(@vals) != 1) {
print "multiple values " . scalar(@vals) ." for $key!\n";
$q->param($key, join (joiner($key), @vals));
}
}
foreach $key (@fields) {
if ($key ne 'body') {
if ($key =~ /[^A-Za-z0-9_-]/) {
print "$0: Ignoring malformed header field named '$key'!\n";
next;
}
print MAIL ucfirst($key) . ": " .
sanitize_field_value($q->param($key)) . "\n"
or die ("$0: Feeding header to sendmail failed: $!\n");
}
}
print MAIL "\n"
or die ("$0: Ending header for sendmail failed: $!\n");
print MAIL $q->param('body'), "\n"
or die ("$0: Feeding body to sendmail failed: $!\n");
close(MAIL)
or warn $! ? "Error closing pipe to sendmail: $!"
: ($? & 127) ? ("Sendmail killed by signal " . ($? & 127) .
($? & 127) ? ", core dumped" : "")
: "Return value " . ($? >> 8) . " from sendmail";
}